Dual Link and SLI

[JackBurton]

Ok, I just wanted to bring this topic up as it has been asked several time, but there has been no real answer (at least I haven't seen one). Does dual link work with SLI? Some people have said dual link does not work with SLI. Well, I'd like to set the record straight by saying it does. It actually is the preferred configuration if you are driving a 30" Apple CD or the new 30" Dells that are coming out. A few nice rich members in the HardOCP forum already have a 30" ACD and two 7800GTX in SLI and the screen shots are AWESOME! Their comments are, a single 7800GTX can drive the display at 2560x1600 but with newer games, it can be pretty "borderline." They seem to be pretty dang happy with SLI and their 30" ACD. I would be too by the screen shots they posted!

Anyway, if this has already been discussed, sorry. I just wanted to throw this out there for people considering an Apple 30" or the upcoming Dell 30" and wondering if SLI would work.

 

[Acanthus]

Dual link and SLI do not work, which is disappointing.

 

[EvilRage]

Nvidia states in their driver reference sheets that the 30" Apple Cinema (and I imagine the Dell 30", because it runs the same res) does not work with SLI. They recommend using a single card. This may not apply to hacked drivers.

 

[JackBurton]

Originally posted by: Acanthus
Dual link and SLI do not work, which is disappointing.

Umm, yes it does. Did you not even read the link? The guy has two GTXs running in SLI with a 30" ACD running at 2560x1600.

 

[JackBurton]

Originally posted by: EvilRage
Nvidia states in their driver reference sheets that the 30" Apple Cinema (and I imagine the Dell 30", because it runs the same res) does not work with SLI. They recommend using a single card. This may not apply to hacked drivers.

Nvidia also states on their 7800GTX cards that 2048 x 1536 is the max resolution.

 

[Acanthus]

Originally posted by: JackBurton

Originally posted by: Acanthus
Dual link and SLI do not work, which is disappointing.

Umm, yes it does. Did you not even read the link? The guy has two GTXs running in SLI with a 30" ACD running at 2560x1600.

The guy uses a 3rd party hack to get it work, it is not officially supported for a reason.

 

[JackBurton]

Originally posted by: Acanthus

Originally posted by: JackBurton

Originally posted by: Acanthus
Dual link and SLI do not work, which is disappointing.

Umm, yes it does. Did you not even read the link? The guy has two GTXs running in SLI with a 30" ACD running at 2560x1600.

The guy uses a 3rd party hack to get it work, it is not officially supported for a reason.

What reason would that be? And what 3rd party hack are you talking about?

 

[Acanthus]

Originally posted by: JackBurton

Originally posted by: Acanthus

Originally posted by: JackBurton

Originally posted by: Acanthus
Dual link and SLI do not work, which is disappointing.

Umm, yes it does. Did you not even read the link? The guy has two GTXs running in SLI with a 30" ACD running at 2560x1600.

The guy uses a 3rd party hack to get it work, it is not officially supported for a reason.

What reason would that be? And what 3rd party hack are you talking about?

Maybe it's not supported because the ramdacs are not rated for that kind of pixel throughput, long term usage may cause damage or not all cards may work properly with dual link + SLI. Hence why it is not officially supported. I dont know, i dont work at Nvidia.

You have an attitude for someone with a question my friend.

 

[CP5670]

I don't think the RAMDAC specs are relevant, since this concerns DVI. On an analog connection it should max out at 2048x1536 at 85hz like any other card(s).

 

[Nextman916]

Originally posted by: Acanthus

Originally posted by: JackBurton

Originally posted by: Acanthus

Originally posted by: JackBurton

Originally posted by: Acanthus
Dual link and SLI do not work, which is disappointing.

Umm, yes it does. Did you not even read the link? The guy has two GTXs running in SLI with a 30" ACD running at 2560x1600.

The guy uses a 3rd party hack to get it work, it is not officially supported for a reason.

What reason would that be? And what 3rd party hack are you talking about?

Its not supported because the ramdacs are not rated for that kind of pixel throughput, long term usage may cause damage or not all cards may work properly with dual link + SLI. Hence why it is not officially supported. I dont know, i dont work at Nvidia.

You have an attitude for someone with a question my friend.

Acanthus i dont beleive he even asked a question in his OP. He was just stating that Dual link w/Sli worked. The only thing he asked is what 3rd party hack could do that, which i did not detect any attitude coming from.

 

[kamranziadar]

Thanx for the screen shot.

 

[Acanthus]

Ok, well it isnt supported officially, and thats what matters.

 

[Acanthus]

Originally posted by: CP5670
I don't think the RAMDAC specs are relevant, since this concerns DVI. On an analog connection it should max out at 2048x1536 at 85hz like any other card(s).

Again, im not a microengineer, and i doubt you are, but nvidia, who has microengineers, and designs the product, decided that it should not be officially supported, why that is, i dont know.

If you want to force the hardware to do it, be my guest, i wouldnt trust ~$4000 in hardware working in an unsupported mode, this isnt exactly a $200 processor we are talking about here... its a $2000+ display and 2 $400+ graphics cards.

 

[JackBurton]

Originally posted by: Nextman916

Originally posted by: Acanthus

Originally posted by: JackBurton

Originally posted by: Acanthus

Originally posted by: JackBurton

Originally posted by: Acanthus
Dual link and SLI do not work, which is disappointing.

Umm, yes it does. Did you not even read the link? The guy has two GTXs running in SLI with a 30" ACD running at 2560x1600.

The guy uses a 3rd party hack to get it work, it is not officially supported for a reason.

What reason would that be? And what 3rd party hack are you talking about?

Its not supported because the ramdacs are not rated for that kind of pixel throughput, long term usage may cause damage or not all cards may work properly with dual link + SLI. Hence why it is not officially supported. I dont know, i dont work at Nvidia.

You have an attitude for someone with a question my friend.

Acanthus i dont beleive he even asked a question in his OP. He was just stating that Dual link w/Sli worked. The only thing he asked is what 3rd party hack could do that, which i did not detect any attitude coming from.

Exactly.

Acanthus, I'm not trying to come off with an attitude, I'm just asking you to back up your claims. Like I said, if you want "official," it looks like nVidia doesn't "officially" support 2560x1600 on a single 7800GTX card yet it is an available resolution when you connect it with an 30" ACD with NO modifications. The link I posted was from a guy running a 30" ACD with an SLI configuration. You mentioned he used a 3rd party hack but I saw no mention from him that he did so. As far as I read, he just plugged in his ACD and SLI worked with it with no problems and no modifications. Like I said, you mentioned a 3rd party hack, I just want to know where you're getting that from.

 

[CP5670]

Originally posted by: Acanthus

Originally posted by: CP5670
I don't think the RAMDAC specs are relevant, since this concerns DVI. On an analog connection it should max out at 2048x1536 at 85hz like any other card(s).

Again, im not a microengineer, and i doubt you are, but nvidia, who has microengineers, and designs the product, decided that it should not be officially supported, why that is, i dont know.

If you want to force the hardware to do it, be my guest, i wouldnt trust ~$4000 in hardware working in an unsupported mode, this isnt exactly a $200 processor we are talking about here... its a $2000+ display and 2 $400+ graphics cards.

If it appears to work okay, I don't see what the risk is. But whatever, I'm personally not too concerned about this as long as SLI has the same maximum analog mode as a single card, which seems to be the case.

 

[JackBurton]

Originally posted by: CP5670

Originally posted by: Acanthus

Originally posted by: CP5670
I don't think the RAMDAC specs are relevant, since this concerns DVI. On an analog connection it should max out at 2048x1536 at 85hz like any other card(s).

Again, im not a microengineer, and i doubt you are, but nvidia, who has microengineers, and designs the product, decided that it should not be officially supported, why that is, i dont know.

If you want to force the hardware to do it, be my guest, i wouldnt trust ~$4000 in hardware working in an unsupported mode, this isnt exactly a $200 processor we are talking about here... its a $2000+ display and 2 $400+ graphics cards.

If it appears to work okay, I don't see what the risk is. But whatever, I'm personally not too concerned about this as long as SLI has the same maximum analog mode as a single card, which seems to be the case.

There is no risk. I don't know what he's talking about. If you plug in a monitor and the resolution is available without any modifications, there is no risk. Come on, seriously. You are not overclocking your card to work out of specs. The certified nVidia drivers have that resolution available right from the get go.

 

[ND40oz]

Will dual link dvi work in a two video card setup not configured in SLI, just 2 video card? I'm planning on going with a Dell 3007 flanked by two 1905s, one on each side. I have the dual 1905s at work already and should have the 3007 shortly. 7800GT for the 30" and a 6800GS for the 1905s.

 

[JackBurton]

Originally posted by: ND40oz
Will dual link dvi work in a two video card setup not configured in SLI, just 2 video card? I'm planning on going with a Dell 3007 flanked by two 1905s, one on each side. I have the dual 1905s at work already and should have the 3007 shortly. 7800GT for the 30" and a 6800GS for the 1905s.

That shouldn't be a problem at all.

 

[Acanthus]

Originally posted by: JackBurton

Originally posted by: Nextman916

Originally posted by: Acanthus

Originally posted by: JackBurton

Originally posted by: Acanthus

Originally posted by: JackBurton

Originally posted by: Acanthus
Dual link and SLI do not work, which is disappointing.

Umm, yes it does. Did you not even read the link? The guy has two GTXs running in SLI with a 30" ACD running at 2560x1600.

The guy uses a 3rd party hack to get it work, it is not officially supported for a reason.

What reason would that be? And what 3rd party hack are you talking about?

Its not supported because the ramdacs are not rated for that kind of pixel throughput, long term usage may cause damage or not all cards may work properly with dual link + SLI. Hence why it is not officially supported. I dont know, i dont work at Nvidia.

You have an attitude for someone with a question my friend.

Acanthus i dont beleive he even asked a question in his OP. He was just stating that Dual link w/Sli worked. The only thing he asked is what 3rd party hack could do that, which i did not detect any attitude coming from.

Exactly.

Acanthus, I'm not trying to come off with an attitude, I'm just asking you to back up your claims. Like I said, if you want "official," it looks like nVidia doesn't "officially" support 2560x1600 on a single 7800GTX card yet it is an available resolution when you connect it with an 30" ACD with NO modifications. The link I posted was from a guy running a 30" ACD with an SLI configuration. You mentioned he used a 3rd party hack but I saw no mention from him that he did so. As far as I read, he just plugged in his ACD and SLI worked with it with no problems and no modifications. Like I said, you mentioned a 3rd party hack, I just want to know where you're getting that from.

Nvidia does support dual link dvi with a single card, i never claimed they didnt.

It is however not officially supported in SLI. There was no recent notes in the most recent driver fixes to denote this either.

He is either using powerstrip or modified shortcuts to "force" the cards to work in 3d over 2048x1536. Furthermore, you almost have to do this to get widescreen resolutions in a lot of games.

What i am saying, and you seem to love to argue with, is that we dont know why nvidia doesnt tout it as some grand featuer over ATi (which it certainly would be) maybe it stresses some components too hard or doesnt work on every pair of cards. Maybe only certain brands use high enough quality parts to make it work. Again, i dont know, and i wouldnt risk it.

"If it appears to work okay, I don't see what the risk is. "

You can run your cpu at 1.9v at the same clockspeed and wont "see" a risk for a while either.

 

[JackBurton]

Originally posted by: Acanthus
Nvidia does support dual link dvi with a single card, i never claimed they didnt.

It is however not officially supported in SLI. There was no recent notes in the most recent driver fixes to denote this either.

He is either using powerstrip or modified shortcuts to "force" the cards to work in 3d over 2048x1536. Furthermore, you almost have to do this to get widescreen resolutions in a lot of games.

What i am saying, and you seem to love to argue with, is that we dont know why nvidia doesnt tout it as some grand featuer over ATi (which it certainly would be) maybe it stresses some components too hard or doesnt work on every pair of cards. Maybe only certain brands use high enough quality parts to make it work. Again, i dont know, and i wouldnt risk it.

"If it appears to work okay, I don't see what the risk is. "

You can run your cpu at 1.9v at the same clockspeed and wont "see" a risk for a while either.

Ok man, I know what the problem is now, you have your facts mixed up. You don't need dual link to run at 2048x1536. A single link card will run at that resolution but only with an analog signal (VGA). You'll need dual link to run a flat panel using DVI for anything greater than 1920x1200. You DO NOT need 3rd party hacks to run a 7800GTX and a 30" ACD at 2560x1600. Let just make that clear. That is the whole point of having dual link. Nvidia only shows a max resolution for their 7800GTXs as 2048x1536, but when you install the "OFFICIAL CERTIFIED" drivers from Nvidia, you'll have the option to choose 2560x1600. No hack, no 3rd party nothing. Sooooo, no damage will be done to the card.

Oh, and getting back to my original point. SLI DOES work with dual link with no "3rd party" hacks. I'll just refer you to the link I posted in my original post as proof.

 

[Acanthus]

Originally posted by: JackBurton

Originally posted by: Acanthus
Nvidia does support dual link dvi with a single card, i never claimed they didnt.

It is however not officially supported in SLI. There was no recent notes in the most recent driver fixes to denote this either.

He is either using powerstrip or modified shortcuts to "force" the cards to work in 3d over 2048x1536. Furthermore, you almost have to do this to get widescreen resolutions in a lot of games.

What i am saying, and you seem to love to argue with, is that we dont know why nvidia doesnt tout it as some grand featuer over ATi (which it certainly would be) maybe it stresses some components too hard or doesnt work on every pair of cards. Maybe only certain brands use high enough quality parts to make it work. Again, i dont know, and i wouldnt risk it.

"If it appears to work okay, I don't see what the risk is. "

You can run your cpu at 1.9v at the same clockspeed and wont "see" a risk for a while either.

Ok man, I know what the problem is now, you have your facts mixed up. You don't need dual link to run at 2048x1536. A single link card will run at that resolution but only with an analog signal (VGA). You'll need dual link to run a flat panel using DVI for anything greater than 1920x1200. You DO NOT need 3rd party hacks to run a 7800GTX and a 30" ACD at 2560x1600. Let just make that clear. That is the whole point of having dual link. Nvidia only shows a max resolution for their 7800GTXs as 2048x1536, but when you install the "OFFICIAL CERTIFIED" drivers from Nvidia, you'll have the option to choose 2560x1600. No hack, no 3rd party nothing. Sooooo, no damage will be done to the card.

Oh, and getting back to my original point. SLI DOES work with dual link with no "3rd party" hacks. I'll just refer you to the link I posted in my original post as proof.

None of them say they are running it natively on SLI, and two mention hacks specifically.

and i said OVER 2048x1536, i am not getting my facts messed up. In SLI Dual link is disabled, 2048x1536 is the highest resolution you can use.

Harsephes who is posting most of the screenshots, is running a single 7800GT.

Blethrow, the other person who has GTX SLI, doesnt say any information at all about how he got to that resolution.

 

[JackBurton]

Originally posted by: Acanthus
None of them say they are running it natively on SLI, and two mention hacks specifically.

and i said OVER 2048x1536, i am not getting my facts messed up. In SLI Dual link is disabled, 2048x1536 is the highest resolution you can use.

Harsephes who is posting most of the screenshots, is running a single 7800GT.

Blethrow, the other person who has GTX SLI, doesnt say any information at all about how he got to that resolution.

Ok man, we need to take this step by step because you are all over the place. Let's start with number one. You said the nVidia cards are rated at 2048x1536 MAX resolution (forget SLI, just a single card with dual link, ie 7800GTX), right? Here is nVidia's specs on the GTX 512MB card:

Dual integrated 400MHz RAMDACs for display resolutions up to and including 2048x1536 at 85Hz

So we've gotten this far, right? Well it is a FACT, as many people have done it at HardOCP, that 2560x1600 is an available resolution with nVidia's "certified drivers," no hack, no 3rd party software. Just go into display properties and set your resolution to 2560x1600. Easy as that. But you are saying someone that runs their single card at 2560x1600 with no mods is running it out of specs and will damage the card which is simply not true. Dual link was the only thing lacking on the PC side (vs the Apple 6800Ultra DDL) that would not be able to drive that display over 1920x1200. Now that the newer gaming cards have dual-link, 2560x1600 is an available resolution. This is just a fact.

Now if you can set one card to 2560x1600, it isn't out of the question the both cards in SLI can run the same resolution. Blethrow said he's running 2560x1600 in SLI and like I said, he mentioned no hacks. What makes you think one card can do 2560x1600, but once you put them in an SLI configuration 2048x1536 all of a sudden becomes the max resolution? ky650 also said that the 30" Apple works fine in SLI, and I take it to mean at native resolution as anything less would not put in the category as "works fine." And if you needed hacks I'd expect for him to say, "it works fine with a hack."

And please, can you point me to the exact page in the HardOCP forum that a member said he used a 3rd party hack to reach 2560x1600? Maybe it's there and I just overlooked it.

 

[Acanthus]

Originally posted by: JackBurton

Originally posted by: Acanthus
None of them say they are running it natively on SLI, and two mention hacks specifically.

and i said OVER 2048x1536, i am not getting my facts messed up. In SLI Dual link is disabled, 2048x1536 is the highest resolution you can use.

Harsephes who is posting most of the screenshots, is running a single 7800GT.

Blethrow, the other person who has GTX SLI, doesnt say any information at all about how he got to that resolution.

Ok man, we need to take this step by step because you are all over the place. Let's start with number one. You said the nVidia cards are rated at 2048x1536 MAX resolution (forget SLI, just a single card with dual link, ie 7800GTX), right? Here is nVidia's specs on the GTX 512MB card:

Dual integrated 400MHz RAMDACs for display resolutions up to and including 2048x1536 at 85Hz

So we've gotten this far, right? Well it is a FACT, as many people have done it at HardOCP, that 2560x1600 is an available resolution with nVidia's "certified drivers," no hack, no 3rd party software. Just go into display properties and set your resolution to 2560x1600. Easy as that. But you are saying someone that runs their single card at 2560x1600 with no mods is running it out of specs and will damage the card which is simply not true. Dual link was the only thing lacking on the PC side (vs the Apple 6800Ultra DDL) that would not be able to drive that display over 1920x1200. Now that the newer gaming cards have dual-link, 2560x1600 is an available resolution. This is just a fact.

Now if you can set one card to 2560x1600, it isn't out of the question the both cards in SLI can run the same resolution. Blethrow said he's running 2560x1600 in SLI and like I said, he mentioned no hacks. What makes you think one card can do 2560x1600, but once you put them in an SLI configuration 2048x1536 all of a sudden becomes the max resolution? ky650 also said that the 30" Apple works fine in SLI, and I take it to mean at native resolution as anything less would not put in the category as "works fine." And if you needed hacks I'd expect for him to say, "it works fine with a hack."

And please, can you point me to the exact page in the HardOCP forum that a member said he used a 3rd party hack to reach 2560x1600? Maybe it's there and I just overlooked it.

I AM NOT TALKING ABOUT SINGLE CARDS I AM TALKING ABOUT SLI.

Stop treating me like im stupid and twisting my words around. FFS read what i am posting.

"Everything is visible at startup.
Right now im playing Dungeon Seige 2, which i used a hack on to get it to play at the screens native res.
Setup was a snap, just unboxed, plugged in and all was well.
I will post picts later."

 

[JackBurton]

Originally posted by: Acanthus
I AM NOT TALKING ABOUT SINGLE CARDS I AM TALKING ABOUT SLI.

Stop treating me like im stupid and twisting my words around. FFS read what i am posting.

You were talking about running a card out of specs? 2560x1600 is out of specs for a single 7800GTX card according to you. Why is running a single card out of specs ok, but running a SLI configured system at the same resolution a risk of damaging the card?

You want more proof that SLI and 2560x1600 works without hacks? Here you go. Again, I didn't see any mention of hacks. Amazing. Now I'd like you to do one thing for me, READ WHAT I POST! I gave you the chance to back up your claims about hacks but you've never come through. You just come up with these BS claims.

 

[Acanthus]

Originally posted by: JackBurton

Originally posted by: Acanthus
I AM NOT TALKING ABOUT SINGLE CARDS I AM TALKING ABOUT SLI.

Stop treating me like im stupid and twisting my words around. FFS read what i am posting.

You were talking about running a card out of specs? 2560x1600 is out of specs for a single 7800GTX card according to you. Why is running a single card out of specs ok, but running a SLI configured system at the same resolution a risk of damaging the card?

You want more proof that SLI and 2560x1600 works without hacks? Here you go. Again, I didn't see any mention of hacks. Amazing. Now I'd like you to do one thing for me, READ WHAT I POST! I gave you the chance to back up your claims about hacks but you've never come through. You just come up with these BS conclusions.

Please point out where i said that a single GTX running in dual link mode is out of spec.

I have only been talking about SLI in the whole thread.

Instead of arguing with you more, i shot an email to evga on the matter.

And on your 2nd link you provided as proof:

"BFG informed me that although it is not supported, they had some reports from customers that SLI at full 2560x1600 works. I have not tried installing the second BFG board as I'm still working out some motherboard stability issues. The two games I've tried (Everquest and Guild Wars) work fine at full resolution."

"Games (EQ2, HL2, Doom3, BF2) have some random flashing (not serious but very annoying) when in 2560x1600 native resolution but it gone away if lower the resolution below 2560x1600. Try to swap the cards didn't cure the problem. Moreover, my display have the famous green/blue flicking pixel problem. "

Comments: Half Life 2 is simply amazing in SLI at max resolution. I periodically get the flickering green snow, but shutting the monitor off and turning it back on clears it. I do hope that the driver allows for lower resolutions so I can run stuff like Battlefield 2 fullscreen

So you, in your attempts to link working SLI, have shown that over 70% of the users there are having problems with dual link + SLI, maybe thats why its not supported?

Go back to your hole.